The extreme limits of divergence between stories descended from a common root are probably reached in the myths of light and darkness with which the present discussion is mainly concerned The subject will be best elucidated by taking a single one of these myths and following its various fortunes through different regions of the Aryan world. The myth of Hercules and Cacus has been treated by M. Breal in an essay which is one of the most valuable contributions ever made to the study of comparative mythology; and while following his footsteps our task will be an easy one.
The battle between Hercules and Cacus, although one of the oldest of the traditions common to the whole Indo-European race, appears in Italy as a purely local legend, and is narrated as such by Virgil, in the eighth book of the AEneid;by Livy, at the beginning of his history; and by Propertius and Ovid. Hercules, journeying through Italy after his victory over Geryon, stops to rest by the bank of the Tiber. While he is taking his repose, the three-headed monster Cacus, a son of Vulcan and a formidable brigand, comes and steals his cattle, and drags them tail-foremost to a secret cavern in the rocks.
But the lowing of the cows arouses Hercules, and he runs toward the cavern where the robber, already frightened, has taken refuge. Armed with a huge flinty rock, he breaks open the entrance of the cavern, and confronts the demon within, who vomits forth flames at him and roars like the thunder in the storm-cloud. After a short combat, his hideous body falls at the feet of the invincible hero, who erects on the spot an altar to Jupiter Inventor, in commemoration of the recovery of his cattle. Ancient Rome teemed with reminiscences of this event, which Livy regarded as first in the long series of the exploits of his countrymen. The place where Hercules pastured his oxen was known long after as the Forum Boarium; near it the Porta Trigemina preserved the recollection of the monster's triple head; and in the time of Diodorus Siculus sight-seers were shown the cavern of Cacus on the slope of the Aventine. Every tenth day the earlier generations of Romans celebrated the victory with solemn sacrifices at the Ara Maxima; and on days of triumph the fortunate general deposited there a tithe of his booty, to be distributed among the citizens.
In this famous myth, however, the god Hercules did not originally figure. The Latin Hercules was an essentially peaceful and domestic deity, watching over households and enclosures, and nearly akin to Terminus and the Penates. He does not appear to have been a solar divinity at all. But the purely accidental resemblance of his name to that of the Greek deity Herakles,[110] and the manifest identity of the Cacus-myth with the story of the victory of Herakles over Geryon, led to the substitution of Hercules for the original hero of the legend, who was none other than Jupiter, called by his Sabine name Sancus. Now Johannes Lydus informs us that, in Sabine, Sancus signified "the sky," a meaning which we have already seen to belong to the name Jupiter. The same substitution of the Greek hero for the Roman divinity led to the alteration of the name of the demon overcome by his thunderbolts. The corrupted title Cacus was supposed to be identical with the Greek word kakos, meaning "evil" and the corruption was suggested by the epithet of Herakles, Alexikakos, or "the averter of ill." Originally, however, the name was Caecius, "he who blinds or darkens," and it corresponds literally to the name of the Greek demon Kaikias, whom an old proverb, preserved by Aulus Gellius, describes as a stealer of the clouds.[111]
[110] There is nothing in common between the names Hercules and Herakles. The latter is a compound, formed like Themistokles; the former is a simple derivative from the root of hercere, "to enclose." If Herakles had any equivalent in Latin, it would necessarily begin with S, and not with H, as septa corresponds to epta, sequor to epomai, etc. It should be noted, however, that Mommsen, in the fourth edition of his History, abandons this view, and observes: "Auch der griechische Herakles ist fruh als Herclus, Hercoles, Hercules in Italien einheimisch und dort in eigenthumlicher Weise aufgefasst worden, wie es scheint zunachst als Gott des gewagten Gewinns und der ausserordentlichen Vermogensvermehrung." Romische Geschichte, I. 181. One would gladly learn Mommsen's reasons for recurring to this apparently less defensible opinion.
[111] For the relations between Sancus and Herakles, see Preller, Romische Mythologie, p. 635; Vollmer, Mythologie, p.
970.
Thus the significance of the myth becomes apparent. The three-headed Cacus is seen to be a near kinsman of Geryon's three-headed dog Orthros, and of the three-headed Kerberos, the hell-hound who guards the dark regions below the horizon.
He is the original werewolf or Rakshasa, the fiend of the storm who steals the bright cattle of Helios, and hides them in the black cavernous rock, from which they are afterwards rescued by the schamir or lightning-stone of the solar hero.
The physical character of the myth is apparent even in the description of Virgil, which reads wonderfully like a Vedic hymn in celebration of the exploits of Indra. But when we turn to the Veda itself, we find the correctness of the interpretation demonstrated again and again, with inexhaustible prodigality of evidence. Here we encounter again the three-headed Orthros under the identical title of Vritra, "he who shrouds or envelops," called also Cushna, "he who parches," Pani, "the robber," and Ahi, "the strangler." In many hymns of the Rig-Veda the story is told over and over, like a musical theme arranged with variations. Indra, the god of light, is a herdsman who tends a herd of bright golden or violet-coloured cattle. Vritra, a snake-like monster with three heads, steals them and hides them in a cavern, but Indra slays him as Jupiter slew Caecius, and the cows are recovered.
